What is the proper way to set up an intricate, behavior-based nurture program?

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What is the proper way to set up an intricate, behavior-based nurture program?

What is the best way to set up this nurture program using nested program/smart campaigns/streams/etc:

Send Email 1

   >If click, send Email 1A

   >If not, send Email 2

If they clicked in Email 1A, send email 1B

If not, send Email 2

and so on.

Here is an image of the workflow I'm trying to set up within Marketo:

Example for Marketo.png